This invention relates to a code correlation arrangement.
A known correlation arrangement includes a low pass filter for an incoming analog signal and a digital code generator, the output of which is multiplied by the filtered signal. The analog resultant is sampled at a rate appropriate to the noise bandwidth and then digitally filtered to reduce noise. It may be noted that a small amount of aliasing will occur due to sampling of the spread noise. Taking the correlation process one stage further, both the lowpass filtered analog signal and the code generator output can be sampled before they are digitally multiplied together, instead of sampling the analog multiplier resultant. Sampling before a digital multiplier will produce an identical result to sampling after an analog multiplier.